Sinteza, karakterizacija i primena biosorbenata na bazi različitih ligno-celuloznih materijala hemijski modifikovanih pomoću AI[sub]2O[sub]3

This dissertation is a part of the research performed within the Grant No. TR 34008. The experimental part of this thesis was done in the Laboratory for applied and industrial chemistry, Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš. Some analyses were done at the Faculty of Engineering and Science, University of Greenwich, UK and the Faculty of Technology in Leskovac, University of Niš. The aim of this doctoral dissertation is the synthesis of new biosorbents by chemical modification of various lignocellulosic materials with Al2O3. Three lignocellulosic biomasses of different origin were used: waste oak wood chips and two types of agro--industrial waste (gourd shell and plum stone). In addition, to increase sorption capacity and the ability for removal of different types of pollutants, chemical modification overcome the differences in the origin and composition of lignocellulose biomasses and the final materials have the same sorption characteristics. The chemical modification of lignocellulosic materials with Al2O3 leads to the creation of new specific active centers on the surface of the biosorbent, where different types of pollutants can be bound (cationic, anionic and nonpolar). By analyzing the principal parameters of the sorption process, the optimal conditions for removal of pollutants from water in the single--component solution, and also simultaneously in the multi--component system, were determined

Ultra-violet responsive photocatalytic application of CuO/Bi oxide nitrate hydroxide hydrate powder

976-983A new photocatalyst CuO/Bi oxide nitrate hydroxide hydrate (C-BONH) has been synthesized by hydrothermal method. The obtained product has been characterized using x-rays diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The surface area has been measured by Brunauer-Emmett-Teller (BET) method, and it has been found 4.42 m2 g–1. The photocatalytic activity has been evaluated by removal of reactive blue 19 (RB 19) dye, where total decolorization has been achieved in less than 15 minutes. The photocatalytic process is described with four kinetic models (Langmuir‒Hinshelwood model, pseudo-first order kinetic model, pseudo-second order kinetic model and Chrastil diffusion model). Langmuir‒Hinshelwood kinetic model and pseudo-first order kinetic model the best describe the photocatalytic process. Chrastil diffusion model has been shown that diffusion has not any influence on the process. The chemical oxygen demand (COD) has been decreased from 28.1 to 6.82 mg dm–3within 180 minusing UV light (254 nm wavelength). It has been observed that photocatalyst retained its stability and activity even after five cycles, which could significantly reduce the operation cost in practical applications

Ultra-violet responsive photocatalytic application of CuO/Bi oxide nitrate hydroxide hydrate powder

A new photocatalyst CuO/Bi oxide nitrate hydroxide hydrate (C-BONH) has been synthesized by hydrothermal method. The obtained product has been characterized using x-rays diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The surface area has been measured by Brunauer-Emmett-Teller (BET) method, and it has been found 4.42 m2 g–1. The photocatalytic activity has been evaluated by removal of reactive blue 19 (RB 19) dye, where total decolorization has been achieved in less than 15 minutes. The photocatalytic process is described with four kinetic models (Langmuir‒Hinshelwood model, pseudo-first order kinetic model, pseudo-second order kinetic model and Chrastil diffusion model). Langmuir‒Hinshelwood kinetic model and pseudo-first order kinetic model the best describe the photocatalytic process. Chrastil diffusion model has been shown that diffusion has not any influence on the process. The chemical oxygen demand (COD) has been decreased from 28.1 to 6.82 mg dm–3within 180 minusing UV light (254 nm wavelength). It has been observed that photocatalyst retained its stability and activity even after five cycles, which could significantly reduce the operation cost in practical applications.

Characterization of a low cost Lagenaria vulgaris based carbon for ranitidine removal from aqueous solutions

Practical aspects of Lagenaria vulgaris shell conversion to activated carbon were examined along with its use in ranitidine adsorption. Kinetics and isotherms of adsorption onto Lagenaria vulgaris carbon (LVC) were correlated to several theoretical adsorption models. The best fit was found in the case of Langmuir and pseudo-second-order model indicating monolayer adsorption. The influence of pH under kinetic study showed slightly hindered adsorption below pH 4. The optimal adsorbent dosage was set to 1 g/L. LVC was characterized by several complementary techniques, including wet chemical techniques such as Boehm's titrations and determination of pH(pzc) and pH of LVC, which revealed neutral nature of the adsorbent. N-2 sorptometry determined specific surface area of 665 m(2)/g and significant ratio of micropores in the sample with maximum wall's diameter of 2.2 nm. Fourier transform infrared spectroscopy (FTIR) confirmed the role of lignin and cellulose in the formation of the final LVC structure. Porous structure of the material was proved by using scanning electron microscopy. Preparation of LVC material drew attention as an easy and low-cost process for production of a highly efficient adsorbent which exhibited fast kinetics of ranitidine removal in the first minutes of contacting and large adsorption capacity (315.5 mg/g) at equilibrium

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second order and Chrastil’s model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g-1 for Cr(III) ions and MB, respectively was obtained at 40 °C, pH 5 and sorbent dose 4 g dm-3 for removal of Cr(III) ions and 1 g dm-3 for removal of MB. The prediction of purification process was successfully carried out and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e. after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm-3. Also, removal of MB from the river water was successfully carried out and after 40 min removal efficiency was about 94 %

Sinteza, karakterizacija i primena biosorbenata na bazi različitih ligno-celuloznih materijala hemijski modifikovanih pomoću AI[sub]2O[sub]3

This dissertation is a part of the research performed within the Grant No. TR 34008. The experimental part of this thesis was done in the Laboratory for applied and industrial chemistry, Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš. Some analyses were done at the Faculty of Engineering and Science, University of Greenwich, UK and the Faculty of Technology in Leskovac, University of Niš. The aim of this doctoral dissertation is the synthesis of new biosorbents by chemical modification of various lignocellulosic materials with Al2O3. Three lignocellulosic biomasses of different origin were used: waste oak wood chips and two types of agro--industrial waste (gourd shell and plum stone). In addition, to increase sorption capacity and the ability for removal of different types of pollutants, chemical modification overcome the differences in the origin and composition of lignocellulose biomasses and the final materials have the same sorption characteristics. The chemical modification of lignocellulosic materials with Al2O3 leads to the creation of new specific active centers on the surface of the biosorbent, where different types of pollutants can be bound (cationic, anionic and nonpolar). By analyzing the principal parameters of the sorption process, the optimal conditions for removal of pollutants from water in the single--component solution, and also simultaneously in the multi--component system, were determined

KARAKTERIZACIJA MODIFIKOVANIH BIOSORBENATA POMOĆU TIO2 I NJIHOVA PRIMENA ZA UKLANJANJE JONA TEŠKIH METALA

Preparation, characterization and application of materials modified with TiO2 nanoparticle have been reviewed. Chitosan, bacterial biomass and dendrimers were the starting material for modification. Sorbents characterization was performed by scanning electron microscopy (SEM). In order to investigate the sorption capabilities of sorbents, we used them for removal of heavy metal ions from aqueous solution. The effect of contact time on heavy metal ions sorption and maximum sorption capacities of biosorbents are shown. As a very important parameter of the sorption process, the effect of initial pH values on heavy metal removal was examined. This paper indicates that sorption using the material modified with TiO2 is becoming a promising alternative to conventional adsorbents in removing heavy metal ions.U ovom radu je predstavljen pregled dobijanja, karakterizacije i primene materija modifikovanih pomoću TiO2 . Kao početni material za modifikaciju korišćeni su citozan, bakterijska biomasa i dendrimeri. Karakterizacija dobijenih sorbenata je rađena primenom skenirajuće elektronske mikroskopije (SEM). Sorbenti su korišćeni za uklanjanje jona teških metala iz vodenih rastvora, u cilju ispitivanja njihovih sorpcione sposobnosti. Prikazan je uticaj kontaktnog vremena na uklanjanje jona teških metala i maksimalni sorpcioni kapacitet biosorbenata. Ispitivan je uticaj inicijalnog pH rastvora na uklanjanje jona teških metala, kao jedan od najbitnijih faktora koji utiče na sorpcioni proces. Rezultati pokazuju da se biosorbenti modifikovani sa TiO2 mogu koristiti kao efikasno sredstvo za uklanjanje jona teških metala iz vode

Synthesis of mesoporous triple-metal nanosorbent from layered double hydroxide as an efficient new sorbent for removal of dye from water and wastewater

In this study, co-precipitation synthesis of the mesoporous triple-metal nanosorbent from Fe, Cu, Ni layered double hydroxide (FeCuNi-LDH), on the basis of the data obtained from the TG analysis was carried out. The FTIR spectroscopy and XRD results confirm the formation of CuO, NiO and Fe O nanoparticles, while the EDX analysis does not show significant variations on the surface in elemental composition. BET analysis shows that FeCuNi-280 (FeCuNi-LDH calcinated at 280 °C) with mesoporous structure, has larger surface area compared to FeCuNi-LDH and FeCuNi-550 (FeCuNi-LDH calcinated at 550 °C). The value of pH of FeCuNi-280 is found to be 8.66. Obtained FeCuNi-280 material showed the ability for efficient removal of dye Reactive Blue 19 (RB19) from water, with a very high sorption capacity of 480.79 mg/g at optimal conditions: the sorbent dose of 0.6 g/dm , stirring speed of 280 rpm and pH 2. The kinetics results of the sorption process were well fitted by pseudo-second order and Chrastil model, and the sorption isotherm was well described by Sips, Langmuir and Brouers-Sotolongo model. FeCuNi-280 was easily regenerated with aqueous solution of NaOH, and reutilization was successfully done in five sorption cycles. The present study show that easy-to-prepare, relatively inexpensive nanosorbent FeCuNi-280 is among the best sorbents for the removal of RB19 dye from water solution and wastewater from textile industry in wide range of pH

Triclinic ZnMoO4 catalyst for atmospheric pressure non-thermal pulsating corona plasma degradation of reactive dye; role of the catalyst in plasma degradation process

Microcrystalline α-ZnMoO4 catalyst for degradation of Reactive Black 5 by self-made open air atmospheric pressure pulsating corona plasma reactor was synthesized by electrodeposition, followed by thermal treatment. The effect of electrodeposition current density on the catalyst’ characteristics was examined by SEM, EDX, FTIR XRD and TG. The catalyst enhanced plasma decolourization rate by 7.5 times. The role of the catalyst in the consumption of plasma generated H2O2 and in dye degradation was examined in details for the first time to the best of our knowledge; the catalyst enhanced the generation of OH radical, a principle dye degradation reagent, by enhancing decomposition of plasma–generated H2O2. The catalyst’ excitation mostly proceeded by the strikes of plasma–generated active species accelerated by electric field, which transferred their energy to the catalyst, causing the creation of electron – holes pairs which attacked H2O2. Decolourization followed pseudo – first order kinetics. Decolourization rate increases with the increase of discharge current density and reactor input voltage. The ratio between cylindrical reactor cell’s diameter and the liquid level in it didn’t affect the decolourization rate. Relatively high energy yield of 1.86 gkWh-1 was achieved for 50% decolourization. TOC removal was 85.4% after 180 minutes of the treatment

Comparison of the advanced oxidation processes in the degradation of pharmaceuticals and pesticides in simulated urban wastewater: Principal component analysis and energy requirements

Pollutants such as pharmaceutical products and pesticides are still present in treated water. Several of these compounds are photoactive. The photodegradation of eight organic pollutants was studied using listed advanced oxidation processes: UV/H2O2, UV/persulfate, Fenton, photo-Fenton and UV/TiO2. The results show that photodegradation is most effective in the first 10 min of treatments in simulated urban wastewater collected from the local Nišava River. To identify the correlation between applied degradation processes as well as the relationship among the structure of investigated compounds and efficiency of degradation, Pearson’s correlation coefficient analysis and principal component analysis (PCA) were performed. The established correlations between the applied processes, as well as the determination of the influence of the structure on the efficiency of degradation, enable a more efficient choice of the degradation procedure, especially in the case of interference. Additionally, process electrical energy consumption and treatment costs for simulated urban wastewater with different pharmaceuticals and pesticides were determined.Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/4477